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Geologica Carpathica, 1994, vol. 45, no. 2
A LATE CRETACEOUS TO PALEOGENE GEODYNAMIC MODEL FOR THE WESTERN CARPATHIANS IN POLAND
Abstract
In the Western Carpathians there is no ophiolite-bearing suture zone known which could form evidence for the presence of an oceanic basement floored basin during the evolution of this mountain chain. From comparisons with the Eastern Alps and Eastern Carpathians the existence of one or several oceanic basins is infered. Actually, the pebble content in Slovakian flysch deposits strongly indicates that the suture was located at the transition between the Inner and Outer Carpathians. Along Alpine continental-oceanic convergence (subduction) zones it is generally observed that oceanic basement was uplifted or obducted. Such a process is documented in coeval marine (frequently turbiditic) sediments by the reworking of ophiolitic detritus (p. p. chromian spinel). We have applied this approach to locate the possible paleogeographic position of such convergence zone(s) by analyzing flysch sandstones for their heavy mineral content from the various paleogeographic domains. In an earlier work (Winkler & Slaczka 1992) we presented data mainly from the Silesian, Dukla and Magura Basin units and concluded that an ophiolite-bearing belt should have existed to the south of the Pieniny Klippen Belt domains. Here we present further data from Late Cretaceous to Eocene sandstones comprised in the Pieniny Klippen Belt, Grajcarek and southern Magura Basin units. After the main discriminating mineral species chromian spinel and garnet we can establish several sandstone groups which correlate with spatial provenance data in the literature. Chromian spinel was reworked in two main pulses: First, during the Late Cretaceous to the Pieniny Basin s. l. and second, after accretion of the Pieniny domain, during Paleocene and Eocene to the Grajcarek and Magura Basins. The ophiolitic and continental basement bearing source terrain was situated in the rear of the Pieniny Basin s. l. and it was brought to erosion from at least the Middle Cretaceous on. It represented probably a subduction related marginal thrusts belt heading the Apulian (Tatra) continental margin and corresponds to the ”Exotic” ridge of earlier authors. The ophiolitic basement rocks included in the marginal thrust belt appear to have been derived from an oceanic domain situated to the south of the Pieniny realm and which was eliminated probably early during Late Cretaceous. This is supposed from facies relations present in the Czorsztyn Ridge and its southern slope series. We suggest that these domains formed a mobile foreland bulge which migrated northwards during Late Cretaceous due to continental collision between the Apulian and Eurasian plates to the south.
Pages:
71 - 82
Published online:
0. 0. 1994